1. Field of the Invention
The present invention relates generally to systems for the filling, transport, and emptying of liquid containers More particularly, the invention concerns a novel, corrosion resistant liquid extraction apparatus that includes a novel plastic valve that can be removably connected to a liquid transport container. In turn, the valve can be interconnected with a specially configured, corrosion-resistant, plastic coupler that operates the valve in a manner to enable fluid to be extracted from the container.
2. Discussion of the Prior Art
The storage and transport of liquids and particularly the storage and transport of hazardous liquids have long presented substantial problems. For many years liquids were stored and transported in throwaway type metal and plastic containers. Typically, such containers were provided with a threaded liquid outlet port, which, after the container was filled, was closed, by some type of threaded cap. The use of these types of containers was costly, inefficient and often hazardous, particularly when the containers were used to store and transport potentially dangerous chemicals.
In recent years substantial efforts have been made to develop new systems to improve container and drum management capabilities, minimize user exposure to hazardous materials and address emerging governmental regulations. These efforts have resulted in the development of several different types of reusable systems for transferring liquid formulations from returnable closed drums and containers. As a general rule, these systems to a greater, or lesser extent, simplify drum emptying, minimize operator hazards, improve cleanliness and eliminate costly waste inherent in prior art disposable container systems. One of the most advanced of such improved systems was developed by and is presently commercially available from Micro Matic, Inc. of Northridge, Calif.
The Micro Matic system, which is described in U.S. Pat. No. 5,901,747 issued to the present inventor, basically comprises a two-part system that includes a coupler operated extractor valve which can be interconnected with a conventional drum via existing threaded connections and a cooperating coupler which connects to the extractor valve to allow drum emptying through the use of a remote pumping system. The extractor valve apparatus includes a valve body and a down tube connected to the valve body, which extends to the bottom of the drum to permit the complete transfer of liquid from the drum.
Another Micro Matic prior art liquid transfer system is described in U.S. Pat. No. 5,944,229 also issued to the present inventor. This invention concerns a novel, tamper-proof, safety valve system that includes a tamper evident valve closure cap that must be broken before liquid can be removed from the container.
The Micro Matic systems, while representing the best of the current state of the art liquid transfer systems, have certain drawbacks which are sought to be overcome by the system of the present invention More particularly, the metal valve and coupler assemblies of the Micro Matic systems are of a relatively complex design making them somewhat difficult and costly fabricate. Further, in some respects these metal assemblies are not well suited for use with various types of hazardous and highly corrosive chemicals that are frequently stored and transported.
As will be better appreciated from the discussion that follows, unlike the prior art Micro Matic systems, the novel valve and coupler of the improved system of the present invention are of an elegantly simple design and are uniquely constructed from a corrosive resistant plastic that is substantially impervious to most corrosive liquids. Additionally, the improved system provides a customer unique, key type coupler-valve mating interface that precludes removal of the drum contents by unauthorized persons
It is an object of the present invention to provide a novel liquid transfer system that includes a valve and coupler assembly of unique design for use in extracting hazardous fluids from a transport container. More particularly, it is an object of the invention to provide a liquid transfer system of the aforementioned character that includes a novel valve and coupler assembly that is of a simple design and is uniquely constructed from a corrosive resistant plastic that is substantially impervious to most corrosive liquids.
Another object of the invention is to provide a system of the character described which improves container and drum management while at the same time significantly reducing the material and labor costs inherent in the fabrication of the prior art liquid transfer systems.
Another object of the invention is to provide a liquid transfer system, which includes a novel plastic valve mechanism, which can be readily removably connected to a container such as a metal or plastic drum, and a novel, plastic coupler mechanism that can be removably coupled with the plastic valve mechanism for operating the valve mechanism. An important aspect of the liquid transfer system resides in the fact that the valve mechanism is specially configured so that only a coupler of a special, mating configuration can be interconnected with the valve mechanism. In this way, couplers and valves can be custom designed for individual users and use of or tampering with containers belonging to the individual user by users of similar systems is positively prevented.
Another object of the invention is to provide a fluid transfer system of the aforementioned character, which is highly reliable in operation, has a long useful life and is easy to use with a minimum amount of instruction being required.
Another object of the invention is to provide a system of the character described in the preceding paragraphs, which is inexpensive to produce and requires minimum maintenance.
In summary, the novel liquid transfer system of the present invention includes a valve and coupler assembly of unique design and a remote pump means that can be connected to the coupler to extract hazardous fluids from a transport container. The plastic valve of the system comprises a valve body that is connected to the container, which includes a coupler receiving portion and a hollow skirt portion, the hollow skirt portion having a spiral groove formed therein. An insert having a central bore is sealably received within the skirt portion for rotational movement by the coupler between a first valve closed position and a second valve open position. A down tube assembly is connected to the valve body and includes a stem portion that is sealably received within the central bore of the insert. The coupler of the liquid transfer system, which includes a fluid outlet passageway in communication with the fluid passageway of the down tube assembly, can be conveniently, removably connected to the valve body for imparting rotation to the insert. The plastic valve further includes a radially outwardly extending protuberance that is closely receivable within said spiral groove of the skirt portion of said valve body and the coupler receiving portion of the valve body is provided with circumferentially spaced openings which receive circumferentially spaced blades provided on the coupler. The insert of the plastic valve, in turn, includes upstanding fingers that are engagable by the spaced-apart blades when the coupler is connected to said valve body. In one form of the invention, the coupler also includes a downwardly extending first sleeve, an upwardly extending second sleeve telescopically received within the first sleeve and biasing means for yieldably resisting telescopic movement of the second sleeve into the first sleeve.